Safety net for a drill rig

ABSTRACT

A safety net for a top drive including: a body having an upper end and a lower end, the upper end including fasteners for connecting the upper end of the safety net to the top drive and the lower end including an inwardly directed return for extending inwardly beneath the underside of the top drive; and an opening through the body for accessing the top drive from outside the net.

BACKGROUND

Top drives are used in drill rigs also called derricks for wellbore operations.

During use top drives are hoisted above the drill floor of a rig sometimes well above personnel working below. It sometimes occurs that parts fall off a top drive during operations and may fall onto the drill floor below. This may cause a safety concern for workers on the rig.

SUMMARY

In accordance with a broad aspect of the present invention, there is provided a safety net for a top drive, the safety net comprising: a body having an upper end and a lower end, the upper end including fasteners for connecting the upper end of the safety net to the top drive and the lower end including an inwardly directed return for extending inwardly beneath the underside of the top drive; and an opening through the body for accessing the top drive from outside the net.

In accordance with another broad aspect of the present invention, there is provided a top drive installation comprising: a top drive supported in a rig, the top drive including a motor housing including a top end, an underside and a quill extending from the underside; a safety net installed on the top drive, the safety net including an upper end; a lower end including an inwardly directed extension for extending inwardly beneath the underside of the top drive; and fasteners for connecting the safety net to the top drive.

It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:

FIG. 1 is a schematic illustration of a top drive and a drill rig system including a safety net.

FIG. 2 is a schematic illustration of a top drive including a safety net installed thereon.

FIG. 3 is a schematic perspective drawing of an upper part of a safety net.

FIG. 4 is a schematic perspective drawing of a lower part of a safety net.

FIG. 5 is a sectional view through flanges of an upper part and a lower part.

FIG. 6 is a schematic perspective drawing of a back up wrench net.

DESCRIPTION OF VARIOUS EMBODIMENTS

The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventor. The detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

A safety net has been invented for preventing material from falling from a top drive to a drill floor therebelow. In one embodiment, a drill rig system for onshore or offshore operations is provided including a rig frame, a top drive suspended in the rig on a block, and a safety net secured about the top drive and extending therebelow to block at least some of the open access below the top drive, such that materials falling by gravity from the top drive may be caught in the net.

Top drives vary in form, configuration and size, depending on various parameters, such as their power rating, manufacturer, power source, mode of operation, etc. However, top drives do have several features in common. For example, with reference to FIG. 1, a top drive 10 is generally suspended in a rig 12 above the drill floor 13 usually by means of a block and hook 14. Top drive 10 generally includes a swivel 10 a, a main housing 10 b that accommodates the gear box and motor, hydraulics and a quill 10 d. Quill 10 d extends out from the underside of the main housing and is driven to rotate by the components in the main housing. A top drive often is also secured through a lateral connection to a torque track arrangement 16. A top drive has numerous items thereon such as caps, covers, bolts, connectors, pins, to name a few, that can work loose, break off, etc. and may drop onto the drill floor.

A safety device includes a net 20 with an upper end 20 a, a lower end 20 b and, possibly if the net is rectangularly formed, sides. The safety device further includes fasteners 24 integrated in or separate from the net for securing the net to a top drive. Fasteners 24 may include one or more of straps, belts, hook and loop connectors, bolts, ties, flanges, catches, etc. Fasteners 24 may be durable and releasable to allow for removable installation.

The net may be formed to cover various parts of the top drive including the main housing, components below the main housing, etc. Net 20, in the illustrated embodiment, covers at least a portion of the main housing 10 b of a top drive. The net may be secured by fasteners 24 to extend down over the top drive main housing and with lower end 20 b coming in below the housing to close off at least some of the openings below the housing. For example, net 20 may be secured as by, and only stated for example, tying off upper end 20 a of the net above, and lower end 20 b of the net below, the top drive main housing 10 b. For example, net 20 a can be formed to extend from a position below block 14 or, possibly, below swivel 10 a and can include a bottom return as by gathering, tapering, forming, fastening, etc. that extends a distance around and beneath the underside of the top drive main housing 10 b.

A top drive generates significant heat during operation. The net may allow ventilation of the top drive and may be heat and oil resistant such that it is not adversely affected by the heat and operational conditions from the top drive. For example, the net may include a plurality of small openings to allow the flow of air therethrough into the top drive. In one embodiment, the net includes a heat resistant, flexible mesh formed of strands interconnected, interlaced, woven or knit to form openings of less than one inch in diameter. For example, a mesh with regular and numerous ½ or ¼ inch openings may be useful to form all or a portion of the net. Such a mesh may catch very small objects such as pins, nuts and bolts while allowing heat to easily dissipate from the top drive.

Net 20 may include access openings 26, such as slots or windows positioned as necessary for access to the top drive, for example for inspection, routine servicing, changing filters, etc.

Access openings 26 may, if desired, include closures 27 such as fasteners, flaps, covers, etc. to close off the openings when access is not required.

Net 20 may further include holes for connections of external parts to the top drive such as, for example, including the connection of hydraulic lines, connection to the torque track, extension therethrough of the quill, pipe handler bails, bail rams, etc. For example, the sides can be formed to create an opening therebetween such that the net can be wrapped around main housing 10 b and secured thereabout but leave a hole between the sides for connection of the top drive to the torque track. Holes can include fittable (i.e. elastomeric, gatherable, etc.) and/or fixed opening sizes.

Referring to FIGS. 2 to 5, another embodiment of a net is shown. The illustrated net includes a plurality of parts such that the parts of the net can be installed on various portions of the top drive and can be interconnected but allow movement therebetween. For example, one net part can be installed in a fixed position on the top drive housing 110 b, while a second net part can be installed on a moveable part of the top drive to move therewith. A connection may be provided between the parts of the net to permit relative movement therebetween.

For example, as shown, the net may include an upper part 150 and a lower part 162. Upper part 150 includes an upper end 151, sides 152, a lower end 153 and fasteners 156 for securing the net in place on a top drive. Upper part 150 is sized and formed to fit about a motor housing 110 b of a top drive. Upper end 151 may be gathered, tapered or otherwise formed if desired to reduce the size thereof. Lower end 153 is gathered as at 153 a, tapered or otherwise formed to neck in around the underside of the motor housing. Sides 152 are selected to be of a length to extend down along the motor housing from upper end 151 to lower end 153.

Lower end 153 further includes an annular flange 158 encircling a lower opening. Flange 158 defines the outer limits of opening 160 and is selected to hold its shape although it may be resilient to allow flex thereof, after which it returns to its original annular shape. Flange 158 forms a swivel support for an upper end of lower part 162 of the net. Flange 158 may include a swivel track 164 thereon and/or a low friction surface, such as may include a low friction upper surface coating such as may include a polytetrafluoroethylene or a polymer with similar properties.

Lower part 162 includes an upper end, a lower end and fasteners 166 for securing the net in place on a top drive. Lower part 162 is sized and formed to fit below motor housing 110 b, and in particular, about the pipe handler, rotary manifold and upper quill sections 110 d of a top drive. As will be appreciated, in some top drives, the pipe handler, rotary manifold and upper quill sections 110 d of some top drives may rotate slightly relative to the top drives motor housing 110 b. Lower part 162 may be configured to allow for such rotation relative to upper part 150, which is secured to motor housing 110 b.

For example, the upper end of lower part 162 may be formed to be supported on annular flange 158 of the upper part 150. In particular, the upper end may include an outwardly extending flange 178 and a body 179 extending downwardly therefrom. Body 179 fits through opening 160 and flange 178 rests on and is supported by flange 158. Flanges 158 and 178 may be formed to coact to allow rotation of the lower part flange 178 on the upper part flange 158 and therefore body 179 within opening 160. Flange 178 may include a swivel track 182 thereon that fits into or engages on swivel track 162 and/or a low friction surface, such as may include a low friction surface coating such as may include a polytetrafluoroethylene or a polymer with similar properties.

Lower part 162 may, therefore, be fixed to the pipe handler and upper quill 110 d to move with them, while remaining connected to, but able to move relative to, upper part 150. Lower part 162 may be fixed to the pipe handler and quill sections in various ways. For example, lower part 162 may include a lower necked region 184 that fits tightly about upper quill 110 d. The tight fit allows the necked region to be substantially secured to move with the quill 110 d. Lower part 162 may further include openings 186, 187 through which the bails 188 or bail ears and bail rams 189, respectively, can be inserted for extension therethrough. Openings 186 may include elastomeric, pleated, etc. forms to ensure that the net is able to move with the parts and allows some flexibility in fit, while seeking to close off gaps therebetween.

Lower part 162 can be formed for installation by pulling up over the parts or may include installation slits 190 and fasteners 190 a to secure the net about the underside components of the top drive. In one embodiment, lower part 162 includes a full length opening defined by sides 191 to allow the net to be installed by wrapping the sides about the top drive components and fitting the bails and bail rams into their openings 186, 187 through slits 190. In such an embodiment, flange 178 may be formed as a c-shaped structure, which can be opened to fit about the top drive components but then return into its annular shape. Flange 178 may therefore be formed of materials that allow it to flex, when force is applied but is resilient to return to its annular shape.

In one possible embodiment, a third part 192 may be provided to fit about a back up wrench 193 of a top drive. Third part 192 may be used separately from or together with parts 150 and 162. Third part 192 may be formed as a sleeve that may be fit over the back up wrench and may include an open upper end 194 including fasteners 195 for securing the net to the upper end of back up wrench 193 and a formed end 196 to fit over the lower, acting end of wrench 193. Formed end 196 may include an opening 197 for passage therethrough of quill 110 d. Opening 197 may include a pair of aligned apertures sized to correspond to the inner diameter through the back up wrench. The body of part 192 between ends 194, 196, may include a slack region 198 to allow for extension of the back wrench therewithin, while ends 194, 196 remain in place on the back up wrench. Slack region 198 may include pleats and/or elastomeric sections to allow the net to extend with the wrench.

Fasteners 156, 166, 195 may take various forms, as noted previously in reference to FIG. 1, and may include more than one form on any particular net part. Some fasteners, such as fasteners 166 may include snaps, catches, bolts, hook and loop-type fasteners to secure two parts of the net together. Alternately or in addition, some other fasteners, for example, fasteners 156 and 195 may include strap or belt forms that permit the net to be secured by wrapping the strap about a point on the top drive. In another embodiment, reinforced eyelets 156 a may be provided to permit bolts, such as bottom housing bolts 199 of the top drive, to be inserted to hold the net in place on a component of the top drive. Referring particularly to the illustrated net's upper part 150, it may include straps 156 for securing the upper end of the upper part 150 to the wash pipe, swivel and/or upper tubes of the traction motor frame. The lower end of the upper part 150 may include reinforced eyelets 156 a positioned to align with and fit over bottom housing bolts 199. The reinforcement 157 about the eyelets 156 a may extend between eyelets and/or to attach to flange 158 such that the flange is firmly supported with eyelets 156 a on bolts 199.

Openings 156 may be provided through the body of the net in any one of the parts to provide access to the top drive therethrough.

To install the upper part 150, the straps 156 may be installed by wrapping and securing about their mounting points and then lower end can be fit about the lower end of the housing 110 b. Nuts on bolts 199 can be removed, eyelets 156 a can be fit over bolts 199 and the nuts reinstalled such that the net is held pinched between the housing and the nuts on bolts 199. In this way, the upper part of net is affixed to the motor housing, without the ability of the upper part net to twist on the housing.

Lower part 162 may be fit over the pipe handler, rotary manifold and quill sections, as for example, by wrapping the net about the parts, as noted previously, and securing the necked region tightly about the quill. The flange 178 is then interfit onto flange 158 for support and relative rotation therebetween.

If used, third part 192 can be fit over the back up wrench by pulling upper end 194 of the net up over the working end and along the telescoping region and securing straps 195 about the wrench upper end. Openings 197 can be adjusted to align with the opening of the working end.

Net parts 150, 162, 192 can be formed to include mesh sections, as described hereinbefore with respect to FIG. 1. The mesh may be formed of heat and oil resistant materials such that they are able to withstand the conditions about the top drive. Materials such as nitrites, polyvinylchloride, etc. may be useful. Mesh sections may be secured to fasteners, edge reinforcements, reinforcements 157, flanges 158, 178, etc. by various means. For example, connections may be by stitching, polymer welding, forming, deformation, etc.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are know or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for”. 

1. A safety net for a top drive, the safety net comprising: a body having an upper end and a lower end, the upper end including fasteners for connecting the upper end of the safety net to the top drive and the lower end including an inwardly directed return for extending inwardly beneath the underside of the top drive; and an opening through the body for accessing the top drive from outside the net.
 2. The safety net of claim 1 further comprising fasteners on the lower end for the lower end of the safety net to the top drive.
 3. The safety net of claim 1 comprising at least one mesh section and reinforcements secured to the at least one mesh section.
 4. The safety net of claim 1 wherein the fasteners include straps.
 5. The safety net of claim 1 further comprising bolt receiving eyelets along the lower end.
 6. The safety net of claim 1 including materials resistant to breakdown by heat and oil.
 7. The safety net of claim 1 further comprising a second net part including a top end supported by the bottom end and a necked portion extending from the top end.
 8. The safety net of claim 7 wherein the lower end includes an annular, inwardly directed flange defining the limits of a lower opening and wherein the second net part includes an annular radially outwardly extending flange on its top end formed to be supported on the annular, inwardly directed flange, while the necked portion extends downwardly through the lower opening.
 9. The safety net of claim 1 further comprising bolt receiving eyelets along the lower end.
 10. The safety net of claim 1 wherein the annular, inwardly directed flange and the annular radially outwardly extending flange coact to allow the second net part to swivel about a long axis passing through the plane of the lower opening.
 11. A top drive installation comprising: a top drive supported in a rig, the top drive including a motor housing including a top end, an underside and a quill extending from the underside; a safety net installed on the top drive, the safety net including an upper end; a lower end including an inwardly directed extension for extending inwardly beneath the underside of the top drive; and fasteners for connecting the safety net to the top drive.
 12. The top drive installation of claim 11 wherein the safety net is installed about the motor housing.
 13. The top drive installation of claim 11 wherein the safety net is installed below the motor housing.
 14. The top drive installation of claim 11 wherein the safety net is installed about the back up wrench.
 15. The top drive installation of claim 11 wherein the safety net includes a first part installed about the motor housing and a second part installed below the motor housing.
 16. The top drive installation of claim 15 wherein the second part is secured to rotate with components below the motor housing, while the first part is fixed to the motor housing.
 17. The top drive installation of claim 15 wherein the second part is rotatable about the axis of rotation of the quill
 18. The top drive installation of claim 17 wherein the second part is supported by and rotates relative to the first part.
 19. The top drive installation of claim 15 wherein the first part is affixed at its bottom end to the motor housing by the lower motor housing bolts. 